Telephone installation



Dec. 3, 1940. HEBEL 2,223,803

TELEPHONE INSTALLATION Filed Sept. 15, 1937 2 Sheets-Sheet 1 Fig.1.

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M. HEBEL 2.Z23,803

TELEPHONE INSTALLATION Filed Sept. 15, 1 937 2 Sheets-Sheet 2 IN VE/V 7" 012 M1 lem HEBEL lira/g 3 ATTORNEYS Patented Dec. 3, 1940 UNITED STATES 2,223,803 TELEPHONE INSTALLATION Martin Hebe], Hechendorf-on-the-Pilsensee,

Upper Bavaria, Germany Application September 15, 1937, Serial No. 163,941

In Germany October 1'7, 1936 l 6 Claims.

This invention relates to telephone installations and to the provision of a supervisory station in installations in which the selectors are set directly by the subscribers, that is to say, without the assistance of storing or translating devices. It is known to provide installations having-storing and translating devices with sup-' ervisory devices which are operated in accordance with the setting and the condition of the storing selector so as to indicate such things as the failure to begin a conversation, failure to commence or to terminate a connection and which switch the caller over to an operator. It is, however, not easy to provide such supervision in installations in which the selectors areset direct by impulses sent out when the calling subscriber dials because there is no member such as a storing device available which is common to all the selectors used in making the connection. In such installations, it is usual merely to indicate the state of operation of the various selectors in the selector racks. Another scheme isto connect a few subscribers to a supervisory station in which the connections made to and from these subscribers are watched and from which the subscribers are notified where need be.

The invention enables the supervision of all connections to be effected simply and thoroughly.

In accordance with the invention, switch means are provided which are dependent upon the receipt of selecting current impulses, further switch means are provided which are dependent upon the called subscribers line being tested and further switch means are provided which are dependent upon the called subscriber replying. These switch means are arranged so as to control a time switch which is itself arranged so as to cause a supervisory station to be seized when it has remained in operation for a prescribed time. ferent signals inthe supervisory station sothat when the latter is seized, the reason becomes immediately apparent. The supervisory device in accordance with the invention thus makes perfect supervision of connections possible in telephone installations having selectors which are set directly by the current impulses dialled by The said switch means may actuate difsupervisory devices in accordance with the invention may be used in connection with large automatic telephone networks.

An example of an arrangement in accordance with the invention is illustrated in the accompanying drawings, in which:

Figure 1 shows diagrammatically the switches used for connecting the supervisorystation in accordance with the invention to a speech linefi' Figure 2 shows the circuits at the calling subscribers end which are used in making the said connection, and

Figure 3 shows the line selector circuits and the circuits associated with the called subscriber which are used in making the said connection.

. The connection of the supervisory station P1 to the speech line a; b depends upon the condition of four contacts 0, k, s and z.

The contact 0 is controlled by a relay which is energized When speech linesare seized, The contact is controlled by a switch, the condition of which is dependent upon the receipt of the selecting current impulses from the calling subscriber. The contacts is actuated by a switch which receives a notification signal sent back from the final selector when the latter has been set'or "when testing of the desired subscribers' lin'eisinitiated. The contact'z is actuated by a switch which is controlled by abackward signal sent out by the final selector when the called subscriber replies and used, as a rule, for meteringpurposes. The supervisory station Pl has a selectorcPA which can be connected to the speech linesa, .b. When the calling subscriber seizes. the speech lines, the contact 0 is closed and the time switch Th is'connected in a circuit running over the contacts 0 and k and the resistance Wl. If; at the end of a certain period of time, no selecting current impulses are sent out by the calling subscriber so that the contact It remains closed, the time switch Th responds and, by means of its contactih closes a circuit for the relay R. in the supervisory station. The relay R responds and, by means of its contact 1', connects the stepping magnet Dm of the selector PA to an interrupter. The wipers of the selector PA are now'stepped until the wiper ca reaches the line determined by the actuated contact 0 and contact k which'is in the normal position. Therelay P is then energised and, by means of its contact 1), interrupts the stepping of the selector PA. At, the same time, the lamp Ni in the circuit of the relay P is lit up and thus indicates to the supervisory station that the calling subscriber has not yet Started to dial. The operator at the super- 55 visory station can then, as soon as she is connected to the line, ask the calling subscriber what he wants.

If, however, the calling subscriber dials within the predetermined period of time, the contact k is thrown and the time switch Th is connected in a circuit including the contacts 0, h, z and s and the resistance W2. If now, the backward signal which indicates that testing of the desired subscribers line has been started, is not received within a certain time, the contact 3 remains unoperated and the time switch Th re sponds and, in a manner similar to that de-' scribed above, causes the lamp Ne to be litup when the wiper d0, finds the line involved. The operator of the supervisory station is thus informed that the calling subscriber has" not prop erly completed the selecting operation necessary for making the connection, in other words, has not completely set the final selector.

It will now be assumed that the backward signal indicating that testing is in operation has been received within the prescribed period, the contact 8 being thus thrown. The circuit for the time switch is in these circumstances opened and a circuit is closed through the contacts 0, k, z and s and the resistance W3. If now the wanted subscriber does not reply within the prescribed period, the time switch Th responds and again causes the supervisory station to be seized. The lamp Nm in the circuit of the wiper cal is this time lit up so as to indicate to the operator that the called subscriber has not replied. This failure to reply may be due to various reasons. If it is because the calling subscriber has dialled a number corresponding to a non-existent line, the supervisory station is connected automatically without it being necessary, as in certain known arrangeme'nts'to connect permanently to they outputs of the line selector special lines leading to an information department; If it is because the called subscriber's line is out of order, the supervisory station is switched in. With the usual arrangements, in such a case, a characteristic signal is given only in the selec tor racks. If it is because the wanted subscriber is absent or engaged and the calling subscriber is holdingon in the hope that the called subscriber will soon be available, it is preferable for an operator to be connected to the calling subscriber by the supervisory device than for the call to be automatically cut off as the calling subscriber can then be informed by the operator and, in future, will refrain from holding on for unnecessarily long periods.

If the calling subscriber replaces his receiver on receiving the automatic signals, the contact (2 is opened and the circuit for the time switch is thus opened. The time switch which is only shown diagrammatically in the drawings can: be of any desired form.

Figures 2 and 3 show an example of the principal circuits which can be utilised to cause actuationof the contacts 0, k, z, and s in the manner and in the circumstancesoutlined above. Figure 1; is to be considered between Figures 2 and 3 so that thespeech lines a, b, in Figure 2 are connected to the linea, b in Figure 3 through the lines a, bin Figure 1. The contacts 0, k, a, s, in Figure l are controlled by the relays C, K, Z, S in the call finder illustrated in Figure 2. When the subscriber TN (Figure 2) lifts his receiver, a circuit is closed through the winding I of his multi-step relay T. On energisation of the winding I, the relay T makes its first step and closes its contacts tl, t2.

The contact t2 closes a circuit which runs over the winding I of a relay N and the winding II of the relay AR of a free call finder AS. The relays N and AR are thus energised. In closing the contact nl closes a circuit for the call finder stepping magnet DAS which, through the interrupted RU, steps the wipersof the call finder until the calling subscribers contacts are reached. A circuit is then closed for the testing relay C. This relay responds and by means of its contact cl opens the circuit for the stepping magnet DAS. The energising circuit for the relay C includes the winding II of the relay T. Energisation of this causes the relay T to make its second step and. open its contacts 233, it and 5. The relay AR is now kept energised through its winding I and the relay N through its winding II. The winding II of the relay AR is connected through the contacts 123, R2 and 06 to a sourceof alternating current DT so that a signal is transmitted to the calling subscriber which indicates that he can start to dial.

, on energisation of the relay 0, the contact 0 s (Figure 1) is also closed and closes the circuit for the time switch device Th.

If the calling subscriber fails to dial within a predetermined time dependent upon the time switch device Th, the supervisory station Pl is connected. to the speech lines a, b, in the manner described in connection with Figure 1 and the lamp N2 is lit so as to indicate to the operator the fact thatthe subscriber has not yet dialled.

If, however, the subscriber dials'within the predetermined time, the relay AR is de-ene'rgised at each current impulse. At the first impulse, the contact (112 closes a circuit for the relay K. This relayis then looked in a circuit closed at its contact Icland by opening its contact k2 disconnects the alternating current source DT. The contact 7c (Figure 1) in these circumstances closes a circuit for the time switch device Th through the resistance W2.

As a result of energisation of the relay C, a circuit is closed for the relay E at the contact arl. At each de-energisati'on of the relay AR, the following circuit is made:

the speech lin'e, g3 (Figure 3), relay RA, a

r The relayRA is energised by each current impulse. Its contact ml closes a circuit for a slowacti ng relay V,-which holds its armature attracted during the reception of a current impulse train. At each current impulse, its contact m2 closes a circuit for the-lifting'magnet VM of the lineselector LW.

- soon as the wipers of the line selector LW leave their normal position," a contact NO is ew.-

At the end of the first current impulse train,

the relay V releases slowly. Its contact vl closes a circuit for the winding I of slow-acting relay U, which responds and by means of its contact a2 preparesa circuit for the winding I of the relay ER while its contact 243 closes a circuit for the rotary magnet RM of the line selector LW through the contact m2, I

By means of the impulses of the second train, the rotary magnet RM is' energised. The relay V is also again energised so that the contacts vi and a4 maintain the winding I of the relay energised: When, at the end of the second current impulse train, the relay V releases its arma- 75 v contact us. (Figure 2) is thus energised and its contact ml ture, the circuit for the testing relay P is closed at the contacts a5 and 02. If the called sub-v scriber is free, the relay P responds and when the relay U drops closes a circuit for the relay ZR. Should the wanted subscriber be engaged, the

' testing relay P cannot respond and relay ZR is not energised.

Release of the relay U causes the b-wire of the speech line to be connected to earth over the The relay M in the call finder AS relays P and ZR of the line selector (Figure 3) cannot respond, the relay M of the call finder (Figure- 2) is continuously energised through the b-wire of the speech line. In these circumstances, the relay N drops and, at its contact 122,

I opens the circuit for the relay C of the call finder AS. Also, its contact 115 opens the circuit for the relay CR of the line selector (Figure 3) and causes the line selector to be released in the known manner.

If however, the called subscriber is available, the relay ZR opens the circuit of the b-wire at its contact zrl shortly after the relay U of the line selector (Figure 3) has dropped. The relay M of the call finder AS then releases again. As the relay D is slow to release, the contact dl remains closed for a short time so that the slowacting relay S responds in a circuit running over the contacts (I I and m2 and is locked in a circuit closed by its contact sl. A source of alternating current RT is thus connected to the winding II of the relay AR over the contacts 113, k2, a4 and s3 so that the calling subscriber receives a signal which indicates to him that the desired subscriber is being rung. The contact s (Figure 1) controlled by the relay S (Figure 2) then disconnects the time switch Th from the resistance W2 and connects it to the resistance W3.

On its response, the relay ZR of the line selector (Figure 3) is locked in a circuit closed by its contact 212 and closes a circuit for the relay Q at its contact zr3. The relay Q therefore responds, closes a circuit for the relay L at its contact ql and connects the source of ringing current RM to the speech line at its contacts q2 and q3. The selected subscriber is now rung. When he removes his receiver, the winding II of the relay U is energised so that the circuit for the relay L is opened at the contact u'l. This relay, therefore releases and closes a circuit for the relay Y at its contact 1. The b-wire of the speech line is then earthed by the contacts yl and zrl so that the relay M of the call finder (Figure 2) again responds. Also, the contact 1 2 opens the locking circuit for the relay ZR so that the latter slowly releases and again interrupts the flow of current through the b-wire. When the relay M of the call finder (Figure 2) responds, a circuit is closed for the relay Z at the contact m3. This relay is then looked in a circuit closed at the contact 2|. When the relay M releases, a circuit is closed for the metering 'ma'gnet ZM at the contacts 2|, s2 and m3, so

transmission of signals to the calling subscriber is interrupted.

I claim:

1;;A telephone installation comprising a calling subscribers station provided with impulse emitting means, a called subscribers station, a line between said subscribers stations provided with impulse receiving means, with automatic selectors, with means for causing the testing of said called subscribers line and with means operated when said called subscriber removes his receiver, a supervising operator, a time switch for connecting said operator to said line and a plurality of contacts controlled by said three means provided in said line arranged in series in the energisation circuit of said time switch.

2. A telephone installation comprising a calling subscribers station provided with impulse emitting means, a called subscribers station, a line between said subscribers stations provided with impulse receiving means, with automatic selectors, with means for causing testing of said called subscribers line and with means operated when said called subscriber removes his receiver, a supervising operator, 2. time switch for connecting said operator to said line, a plurality of contacts arranged in series in the energisation circuit of said time switch and controlled by said three means provided in said line and a plurality of signaling devices adapted to emit signals to said operator, each of said signaling devices being controlled by one of said contacts.

3. A telephone installation comprising at least one unattended and one attended exchange, a calling subscribers station provided with impulse emitting means, a called subscribers station, a line between said subscribers stations provided with impulse receiving means, with automatic selectors, with means for causing testing of said called subscribers line and with means responsive on said called subscriber removing his receiver, a supervising operator in the attended exchange, a time switch for connecting said operator to said line, a plurality of signaling devices adapted to emit signals to said operator and a plurality of contacts controlled by said impulse receiving means, by said means for causing testing and by said means responsive on said called subscriber removing his receiver and adapted to control said time switch means and said signaling devices.

4. An automatic telephone installation comprising a calling subscriber, a called subscriber,

a connecting path between said subscribers comprising impulse receiving means, automatic selectors controlled by said impulse receiving means, means for testing said called subscriber, means operated when said called subscriber removes his receiver, a supervising operator, means for connecting said operator to said connecting path, a plurality of signalling devices adapted to emit different signals to said operator, time switch means operated on seizure of said connecting path by said calling subscriber to cause said operator to be connected to said connecting path and to switch in one of said signalling devices, means operated by said impulse receiving means for controlling said time switch means, means operated by said testing means for controlling said time switch means and means operated when said called subscriber removes his receiver for controlling said time switch means.

5. In an automatic telephone installation the combination of a calling subscriber provided with dialling means, a called subscriber, a connecting path connecting said calling subscriber to said called subscriber comprising seizing actuated upon the seizure of said connecting path by said calling subscriber, impulse receiving means, automatic selectors controlled by said impulse receiving means, means for testing said "called subscriber and means actuated upon the response of said called subscriber, time switch means adapted to be made efiective by said seizing means, by said automatic selectors, by said testing means and by said means controlled upon the response of said called subscriber, a supervising operator, a plurality of signalling devices adapted toemit different signals to said operator, one of said devices being prepared by said seizing means, another by said automatic selectors and another by said testing means and means controlled by said time switch means for switching in a prepared one of said signalling devices and for connecting said operator to said connecting path.

6. In an automatic telephone installation the combination of a calling subscribers station provided with dialling means, a called subscribers station, a connecting path between said subamass 'scriibers stations, provided with seizing means means for testing the called subscriber and with 5 means responsive when said called subscriber removes his receiver, a supervising operator, a plurality of signalling devices situated at. said operators position, time switch means, actuating circuits for said time switch means, a series 1 of contactsin said actuating circuits, one of said contacts being adapted to p'repareone of said signalling devices and being controlled by said seizing means, another of said contacts being controlled by said selected means and being 1 adapted to prepare a circuit for another of said signalling devices and another of said contacts being controlled by said testing means and adapted to prepare a circuit for another of said signalling devices, and means controlled by said time switch means for closing a prepared one of said circuits for saidsignalling devices and'for connecting said operator to said connecting path seized by said calling subscriber.

MARTIN HEBEL. 2 

